Four Aerojet AJ60 Solid Rocket Boosters (SRBs) igniting at lift-off increased the launch thrust of United Launch Alliance's Atlas V rocket by more than 1.5 million pounds. All Atlas V launches requiring extra boost performance have flown Aerojet-produced SRBs. These motors have demonstrated a 100 percent success record in flight, having flown 13 missions with vehicle configurations ranging from one to five SRBs.

Eight Aerojet retro rockets also assisted with the Atlas Centaur separation from the launch vehicle approximately 4.5 minutes into flight. In addition, 12 Aerojet monopropellant (hydrazine) thrusters on the Atlas V Centaur upper stage provided roll, pitch and yaw control as well as settling burns for the upper stage main engine.

Now, flying separate from its launch vehicle, the MSL payload is carrying eight Aerojet MR 111C 1.0lbf thrusters that will be used for trajectory correction maneuvers during the transit to Mars and eight Aerojet MR-107U 68 lbf thrusters that will stabilize the spacecraft during its entry. Additionally, the MSL Sky Crane that will do the final lowering of the payload to the Martian surface includes eight Aerojet MR-80B 800-lbf thrusters with a throttleable thrust range of >100:1.

"Aerojet's heritage in Mars exploration dates back to Viking when we provided the original version of the throttleable MR-80 thruster for both successful Viking landings," said Julie Van Kleeck, Aerojet vice president of Space and Launch Systems. "Since then, Aerojet's high-reliability propulsion has been trusted on every U.S. Mars mission, including the only other successful propulsive landing on Mars -- the Mars Phoenix lander in 2008."

Aerojet manufactured the Atlas V Solid Rocket Boosters at its Sacramento, Calif. facility. The retro rockets were designed and developed by Aerojet in Gainesville, Va. and manufactured in Camden, Ark. The three different types of thrusters aboard the MSL were designed and manufactured at Aerojet's Redmond, Wash. facility.

MSL is expected to arrive on Mars in 2012 with its "Curiosity" rover that will house the most advanced scientific instruments ever sent to the Martian surface and that will collect data to help assess if Mars was, or still is, habitable for microbial life.

Aerojet is a world-recognized aerospace and defense leader principally serving the missile and space propulsion, defense and armaments markets. GenCorp is a leading technology-based manufacturer of aerospace and defense products and systems with a real estate segment that includes activities related to the entitlement, sale, and leasing of the company's excess real estate assets. Additional information about Aerojet and GenCorp can be obtained by visiting the companies' websites at http://www.Aerojet.com and http://www.GenCorp.com.